/*
   Copyright (c) 2011, Oracle and/or its affiliates. All rights reserved.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; version 2 of the License.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301  USA
*/

#include "ndb_thd_ndb.h"

/*
  Default value for max number of transactions createable against NDB from
  the handler. Should really be 2 but there is a transaction to much allocated
  when lock table is used, and one extra to used for global schema lock.
*/
static const int MAX_TRANSACTIONS = 4;


Thd_ndb *Thd_ndb::seize(THD *thd)
{
    DBUG_ENTER("seize_thd_ndb");
    Thd_ndb *thd_ndb = new Thd_ndb(thd);

    if (thd_ndb == NULL)
        return NULL;

    if (thd_ndb->ndb->init(MAX_TRANSACTIONS) != 0) {
        DBUG_PRINT("error", ("Ndb::init failed, eror: %d  message: %s",
                             thd_ndb->ndb->getNdbError().code,
                             thd_ndb->ndb->getNdbError().message));
        delete thd_ndb;
        thd_ndb = NULL;
    }

    DBUG_RETURN(thd_ndb);
}


void Thd_ndb::release(Thd_ndb *thd_ndb)
{
    DBUG_ENTER("release_thd_ndb");
    delete thd_ndb;
    DBUG_VOID_RETURN;
}


bool Thd_ndb::recycle_ndb(THD *thd)
{
    DBUG_ENTER("recycle_ndb");
    DBUG_PRINT("enter", ("ndb: 0x%lx", (long)ndb));
    DBUG_ASSERT(global_schema_lock_trans == NULL);
    DBUG_ASSERT(trans == NULL);
    delete ndb;

    if ((ndb = new Ndb(connection, "")) == NULL) {
        DBUG_PRINT("error", ("failed to allocate Ndb object"));
        DBUG_RETURN(false);
    }

    if (ndb->init(MAX_TRANSACTIONS) != 0) {
        delete ndb;
        ndb = NULL;
        DBUG_PRINT("error", ("Ndb::init failed, %d  message: %s",
                             ndb->getNdbError().code,
                             ndb->getNdbError().message));
        DBUG_RETURN(false);
    }

    DBUG_RETURN(true);
}


bool Thd_ndb::valid_ndb(void)
{
    // The ndb object should be valid as long as a
    // global schema lock transaction is ongoing
    if (global_schema_lock_trans)
        return true;

    // The ndb object should be valid as long as a
    // transaction is ongoing
    if (trans)
        return true;

    if (unlikely(m_connect_count != connection->get_connect_count()))
        return false;

    return true;
}


void Thd_ndb::init_open_tables()
{
    count = 0;
    m_error = FALSE;
    my_hash_reset(&open_tables);
}
